From: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Date: Fri, 1 Oct 2021 15:03:47 +0200
Subject: bpf/tests: Add test of ALU shifts with operand register aliasing
Patch-mainline: v5.16-rc1
Git-commit: 68813605dea69ca0af26af7dd00384c78c1df05d
References: jsc#PED-1377
This patch adds a tests of ALU32 and ALU64 LSH/RSH/ARSH operations for the
case when the two operands are the same register. Mainly intended to test
JITs that implement ALU64 shifts with 32-bit CPU instructions.
Also renamed related helper functions for consistency with the new tests.
Signed-off-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20211001130348.3670534-10-johan.almbladh@anyfinetworks.com
Acked-by: Shung-Hsi Yu <shung-hsi.yu@suse.com>
---
lib/test_bpf.c | 162 ++++++++++++++++++++++++++++++++++++++++++++++++++++-----
1 file changed, 149 insertions(+), 13 deletions(-)
--- a/lib/test_bpf.c
+++ b/lib/test_bpf.c
@@ -660,37 +660,37 @@ static int __bpf_fill_alu_shift(struct b
self->u.ptr.insns = insn;
self->u.ptr.len = len;
- BUG_ON(i > len);
+ BUG_ON(i != len);
return 0;
}
-static int bpf_fill_alu_lsh_imm(struct bpf_test *self)
+static int bpf_fill_alu64_lsh_imm(struct bpf_test *self)
{
return __bpf_fill_alu_shift(self, BPF_LSH, BPF_K, false);
}
-static int bpf_fill_alu_rsh_imm(struct bpf_test *self)
+static int bpf_fill_alu64_rsh_imm(struct bpf_test *self)
{
return __bpf_fill_alu_shift(self, BPF_RSH, BPF_K, false);
}
-static int bpf_fill_alu_arsh_imm(struct bpf_test *self)
+static int bpf_fill_alu64_arsh_imm(struct bpf_test *self)
{
return __bpf_fill_alu_shift(self, BPF_ARSH, BPF_K, false);
}
-static int bpf_fill_alu_lsh_reg(struct bpf_test *self)
+static int bpf_fill_alu64_lsh_reg(struct bpf_test *self)
{
return __bpf_fill_alu_shift(self, BPF_LSH, BPF_X, false);
}
-static int bpf_fill_alu_rsh_reg(struct bpf_test *self)
+static int bpf_fill_alu64_rsh_reg(struct bpf_test *self)
{
return __bpf_fill_alu_shift(self, BPF_RSH, BPF_X, false);
}
-static int bpf_fill_alu_arsh_reg(struct bpf_test *self)
+static int bpf_fill_alu64_arsh_reg(struct bpf_test *self)
{
return __bpf_fill_alu_shift(self, BPF_ARSH, BPF_X, false);
}
@@ -726,6 +726,86 @@ static int bpf_fill_alu32_arsh_reg(struc
}
/*
+ * Test an ALU register shift operation for all valid shift values
+ * for the case when the source and destination are the same.
+ */
+static int __bpf_fill_alu_shift_same_reg(struct bpf_test *self, u8 op,
+ bool alu32)
+{
+ int bits = alu32 ? 32 : 64;
+ int len = 3 + 6 * bits;
+ struct bpf_insn *insn;
+ int i = 0;
+ u64 val;
+
+ insn = kmalloc_array(len, sizeof(*insn), GFP_KERNEL);
+ if (!insn)
+ return -ENOMEM;
+
+ insn[i++] = BPF_ALU64_IMM(BPF_MOV, R0, 0);
+
+ for (val = 0; val < bits; val++) {
+ u64 res;
+
+ /* Perform operation */
+ insn[i++] = BPF_ALU64_IMM(BPF_MOV, R1, val);
+ if (alu32)
+ insn[i++] = BPF_ALU32_REG(op, R1, R1);
+ else
+ insn[i++] = BPF_ALU64_REG(op, R1, R1);
+
+ /* Compute the reference result */
+ __bpf_alu_result(&res, val, val, op);
+ if (alu32)
+ res = (u32)res;
+ i += __bpf_ld_imm64(&insn[i], R2, res);
+
+ /* Check the actual result */
+ insn[i++] = BPF_JMP_REG(BPF_JEQ, R1, R2, 1);
+ insn[i++] = BPF_EXIT_INSN();
+ }
+
+ insn[i++] = BPF_ALU64_IMM(BPF_MOV, R0, 1);
+ insn[i++] = BPF_EXIT_INSN();
+
+ self->u.ptr.insns = insn;
+ self->u.ptr.len = len;
+ BUG_ON(i != len);
+
+ return 0;
+}
+
+static int bpf_fill_alu64_lsh_same_reg(struct bpf_test *self)
+{
+ return __bpf_fill_alu_shift_same_reg(self, BPF_LSH, false);
+}
+
+static int bpf_fill_alu64_rsh_same_reg(struct bpf_test *self)
+{
+ return __bpf_fill_alu_shift_same_reg(self, BPF_RSH, false);
+}
+
+static int bpf_fill_alu64_arsh_same_reg(struct bpf_test *self)
+{
+ return __bpf_fill_alu_shift_same_reg(self, BPF_ARSH, false);
+}
+
+static int bpf_fill_alu32_lsh_same_reg(struct bpf_test *self)
+{
+ return __bpf_fill_alu_shift_same_reg(self, BPF_LSH, true);
+}
+
+static int bpf_fill_alu32_rsh_same_reg(struct bpf_test *self)
+{
+ return __bpf_fill_alu_shift_same_reg(self, BPF_RSH, true);
+}
+
+static int bpf_fill_alu32_arsh_same_reg(struct bpf_test *self)
+{
+ return __bpf_fill_alu_shift_same_reg(self, BPF_ARSH, true);
+}
+
+/*
* Common operand pattern generator for exhaustive power-of-two magnitudes
* tests. The block size parameters can be adjusted to increase/reduce the
* number of combinatons tested and thereby execution speed and memory
@@ -11788,7 +11868,7 @@ static struct bpf_test tests[] = {
INTERNAL | FLAG_NO_DATA,
{ },
{ { 0, 1 } },
- .fill_helper = bpf_fill_alu_lsh_imm,
+ .fill_helper = bpf_fill_alu64_lsh_imm,
},
{
"ALU64_RSH_K: all shift values",
@@ -11796,7 +11876,7 @@ static struct bpf_test tests[] = {
INTERNAL | FLAG_NO_DATA,
{ },
{ { 0, 1 } },
- .fill_helper = bpf_fill_alu_rsh_imm,
+ .fill_helper = bpf_fill_alu64_rsh_imm,
},
{
"ALU64_ARSH_K: all shift values",
@@ -11804,7 +11884,7 @@ static struct bpf_test tests[] = {
INTERNAL | FLAG_NO_DATA,
{ },
{ { 0, 1 } },
- .fill_helper = bpf_fill_alu_arsh_imm,
+ .fill_helper = bpf_fill_alu64_arsh_imm,
},
{
"ALU64_LSH_X: all shift values",
@@ -11812,7 +11892,7 @@ static struct bpf_test tests[] = {
INTERNAL | FLAG_NO_DATA,
{ },
{ { 0, 1 } },
- .fill_helper = bpf_fill_alu_lsh_reg,
+ .fill_helper = bpf_fill_alu64_lsh_reg,
},
{
"ALU64_RSH_X: all shift values",
@@ -11820,7 +11900,7 @@ static struct bpf_test tests[] = {
INTERNAL | FLAG_NO_DATA,
{ },
{ { 0, 1 } },
- .fill_helper = bpf_fill_alu_rsh_reg,
+ .fill_helper = bpf_fill_alu64_rsh_reg,
},
{
"ALU64_ARSH_X: all shift values",
@@ -11828,7 +11908,7 @@ static struct bpf_test tests[] = {
INTERNAL | FLAG_NO_DATA,
{ },
{ { 0, 1 } },
- .fill_helper = bpf_fill_alu_arsh_reg,
+ .fill_helper = bpf_fill_alu64_arsh_reg,
},
/* Exhaustive test of ALU32 shift operations */
{
@@ -11879,6 +11959,62 @@ static struct bpf_test tests[] = {
{ { 0, 1 } },
.fill_helper = bpf_fill_alu32_arsh_reg,
},
+ /*
+ * Exhaustive test of ALU64 shift operations when
+ * source and destination register are the same.
+ */
+ {
+ "ALU64_LSH_X: all shift values with the same register",
+ { },
+ INTERNAL | FLAG_NO_DATA,
+ { },
+ { { 0, 1 } },
+ .fill_helper = bpf_fill_alu64_lsh_same_reg,
+ },
+ {
+ "ALU64_RSH_X: all shift values with the same register",
+ { },
+ INTERNAL | FLAG_NO_DATA,
+ { },
+ { { 0, 1 } },
+ .fill_helper = bpf_fill_alu64_rsh_same_reg,
+ },
+ {
+ "ALU64_ARSH_X: all shift values with the same register",
+ { },
+ INTERNAL | FLAG_NO_DATA,
+ { },
+ { { 0, 1 } },
+ .fill_helper = bpf_fill_alu64_arsh_same_reg,
+ },
+ /*
+ * Exhaustive test of ALU32 shift operations when
+ * source and destination register are the same.
+ */
+ {
+ "ALU32_LSH_X: all shift values with the same register",
+ { },
+ INTERNAL | FLAG_NO_DATA,
+ { },
+ { { 0, 1 } },
+ .fill_helper = bpf_fill_alu32_lsh_same_reg,
+ },
+ {
+ "ALU32_RSH_X: all shift values with the same register",
+ { },
+ INTERNAL | FLAG_NO_DATA,
+ { },
+ { { 0, 1 } },
+ .fill_helper = bpf_fill_alu32_rsh_same_reg,
+ },
+ {
+ "ALU32_ARSH_X: all shift values with the same register",
+ { },
+ INTERNAL | FLAG_NO_DATA,
+ { },
+ { { 0, 1 } },
+ .fill_helper = bpf_fill_alu32_arsh_same_reg,
+ },
/* ALU64 immediate magnitudes */
{
"ALU64_MOV_K: all immediate value magnitudes",